STIHL BT 131 User manual

STIHL BT 131

Instruction Manual

Notice d’emploi

G Instruction Manual

1 - 26

F Notice d’emploi

27 - 55

Original Instruction ManualPrinted on chlorine-free paper

Printing inks contain vegetable oils, paper can be recycled.

0458-529-8221-A. VA3.E20.

0000007599_004_GB

BT 131

English

1

with electronic systems.

Contents

Dear Customer,

Thank you for choosing a quality

engineered STIHL product.

It has been built using modern

production techniques and

comprehensive quality assurance.

Every effort has been made to ensure

your satisfaction and trouble-free use of

the product.

Please contact your dealer or our sales

company if you have any queries

concerning this product.

Your

Dr. Nikolas Stihl

Guide to Using this Manual 2

Safety Precautions and Working

Techniques 2

Assembling the Unit 7

Adjusting the Throttle Cable 8

Fuel 8

Fueling 10

Auger Brake 10

Fitting the Auger 11

Starting / Stopping the Engine 12

Operating Instructions 14

Releasing a Trapped Auger 14

Replacing the Air Filter 15

Engine Management 15

Adjusting the Carburetor 16

Spark Arresting Screen in Muffler 16

Spark Plug 16

Engine Running Behavior 17

Lubricating the Gearbox 18

Storing the Machine 18

Maintenance and Care 19

Main Parts 21

Specifications 22

Maintenance and Repairs 23

Disposal 24

STIHL Limited Emission Control

Warranty Statement 24

BT 131

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2

Pictograms

The meanings of the pictograms

attached to the machine are explained in

this manual.

Depending on the model concerned, the

following pictograms may be attached to

your machine.

Symbols in text

WARNING

Warning where there is a risk of an

accident or personal injury or serious

damage to property.

NOTICE

Caution where there is a risk of

damaging the machine or its individual

components.

Engineering improvements

STIHL's philosophy is to continually

improve all of its products. For this

reason we may modify the design,

engineering and appearance of our

products periodically.

Therefore, some changes, modifications

and improvements may not be covered

in this manual.

Observe all applicable local safety

regulations, e.g. by trade organizations,

social insurance institutions, labor safety

authorities etc.

If you have never used a power tool

before: Have your dealer or other

experienced user show you how to

operate your machine – or attend a

special course to learn how to operate it.

Minors are not allowed to work with the

power tool – except adolescents above

16 years of age who are instructed

under supervision.

Children, animals and bystanders must

not be allowed near the machine.

When not using the machine, it must be

laid down in such a way that it does not

endanger anyone. Ensure that the

machine cannot be used without

authorization.

Guide to Using this Manual

Fuel tank; fuel mixture of

gasoline and engine oil

Operate manual fuel

pump

Auger brake

Safety Precautions and

Working Techniques

Special safety precau

-

tions must be observed

when working with this

power tool because of its

high torque and the high

speed of the auger bit in

certain applications, and

because the auger bits

have sharp edges.

It is important you read

and understand the

instructions for use

before first use and keep

it in a safe place for future

reference. Non-compli

-

ance with the User

Manual may cause seri

-

ous or even fatal injury.

BT 131

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The user is responsible for accidents or

risks involving third parties or their

property.

Do not lend or rent your power tool

without the User Manual. Be sure that

anyone using it understands the

information contained in this manual.

The use of machines that emit noise

may be limited to certain hours of the

day as specified by national and/or

regional or local regulations.

Anyone operating the machine must be

well rested, in good physical health and

in good mental condition.

If you have any condition that might be

aggravated by strenuous work, check

with your doctor before operating a

machine.

If you have a pacemaker: The ignition

system of your machine produces an

electromagnetic field of very low

intensity. This field may interfere with

some pacemakers. STIHL recommends

that persons with pacemakers consult

their physician and the pacemaker

manufacturer to reduce any health risk.

Anyone who has consumed alcohol or

drugs or medicines affecting their ability

to react must not operate a power tool.

Use your power tool only for drilling

holes in soil, ice and wood – depending

on the drilling tool mounted. Select the

drill axis so that the lever of the drill

brake can be supported on the thigh of

the operator at any time during drilling.

It must not be used for any other

purposes.

Before drilling, make sure that there are

no lines (e. g. for gas, water, electricity)

at the drilling sites:

– Obtain information from the local

utility companies

– If in doubt, check the existence of

lines with detectors or test

excavations

Only use augers or accessories which

have been approved by STIHL for this

machine or which are technically

equivalent. If you have any questions in

this respect, consult your dealer. Use

only high quality parts and accessories.

in order to avoid the risk of accidents

and damage to the machine.

STIHL recommends the use of original

STIHL tools and accessories. They are

specifically designed to match the

product and meet your performance

requirements.

Never attempt to modify your power tool

in any way since this may increase the

risk of personal injury. STIHL excludes

all liability for personal injury and

damage to property caused while using

unauthorized attachments.

Do not use a high-pressure washer to

clean the power tool. The solid jet of

water may damage parts of the unit.

Clothing and equipment

Wear proper protective clothing and

equipment.

Do not wear clothing which could

become trapped in wood, brush or

moving parts of the machine. Do not

wear a scarf, necktie or jewelry.

WARNING

Wear hearing protection, e.g. ear

defenders.

Wear a safety hard hat where there is a

danger of head injuries from falling

objects.

Clothing must be sturdy

but allow complete free

-

dom of movement. Wear

close-fitting clothes such

as a boiler suit, not a

loose jacket.

Tie up and confine long

hair above your

shoulders.

Wear sturdy shoes with

non-slip soles.

To reduce the risk of eye

injuries, wear close-fit

-

ting safety glasses in

accordance with Euro

-

pean Standard EN 166.

Make sure the safety

glasses are a snug fit.

Wear sturdy protective

gloves made of a resist

-

ant material (e. g.

leather).

BT 131

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STIHL can supply a comprehensive

range of personal protective equipment.

Transporting the machine

Always stop the engine.

Remove the auger before transporting

the power tool long distances. To reduce

the risk of burn injury, carry the unit by

the handle frame with hot parts of the

machine (e.g. gearbox) away from your

body.

By vehicle: When transporting in a

vehicle, properly secure your machine to

prevent turnover, damage and fuel

spillage.

Refueling

Always shut off the engine before

refueling.

Do not fuel a hot engine – fuel may spill

and cause a fire!

Open the fuel cap carefully to allow any

pressure build-up in the tank to release

slowly and avoid fuel spillage.

Only refuel the machine in a well

ventilated place. If fuel has been spilled,

immediately clean the machine – do not

allow your clothes to be splashed with

fuel. If that happens, change your

clothes at once.

This helps reduce the risk of unit

vibrations causing an incorrectly

tightened fuel cap to loosen or come off

and spill quantities of fuel.

Before starting

Check that your power tool is properly

assembled and in good condition – refer

to appropriate chapters in the

instructions for use.

– Check the fuel system for leaks,

especially the visible parts, e. g.,

fuel cap, hose connections, manual

fuel pump (only in machines with a

manual fuel pump). In case of

leakage and damage, do not start

the engine – risk of fire! Have the

machine serviced by a dealer

before using it

– The stop switch must be easy to

push

– Functional drill brake

– Check the choke lever, throttle

trigger and throttle trigger lockout

for smooth action - throttle trigger

must return automatically to idle

position. The choke lever must

spring back from the g and <

positions to the run position F when

the throttle trigger lockout and

throttle trigger are squeezed

– Check that the spark plug boot is

secure – a loose boot may cause

arcing that could ignite combustible

fumes and cause a fire!

– Never attempt to modify the controls

or safety devices

– Keep the handles dry and clean –

free from oil and dirt – this is

important for safe control of the

machine

To reduce the risk of personal injury, do

not operate your power tool if it is

damaged or not properly assembled!

Starting the engine

Start the engine at least 3 meters from

the fueling spot, outdoors only.

Place the power tool on level ground,

make sure you have secure footing.

Engage the drill brake before starting.

Otherwise, the drilling tool may begin to

run, causing the user to lose control of

the earth auger.

The machine is operated by a single

person only – do not allow any person to

stay within the working area – nor with

starting.

To reduce the risk of injury, avoid

contact with the drilling tool.

Gasoline is highly flam

-

mable – keep away from

fire or flame – do not spill

any fuel – no smoking.

After fueling, tighten

down the screw-type fuel

cap as securely as

possible.

Check for fuel leakage!

Never start the engine if

fuel has been spilled or is

leaking – Fatal burns may

result!

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Do not drop-start the engine – start it as

described in the instructions for use.

Check idle speed setting: The drilling

tool must not rotate when the engine is

idling with the throttle trigger released.

Keep easily combustible materials (e.g.,

wood chips, bark, dry grass, fuel) away

from hot exhaust gases and the hot

muffler surface – risk of fire!

Holding and guiding the machine

Always hold the unit firmly with both

hands on the handles.

Ensure you always have a firm and safe

footing – drill brake on left thigh.

Firmly grasp the handles with the

thumbs, left hand on control handle.

While working

Make sure you always have good

balance and secure footing.

In the event of impending danger or in

an emergency, switch off the engine

immediately by pressing the stop switch.

Do not allow any other persons in the

work area. Keep well away from other

people – risk of accidents!

Check for correct idling, so that the

auger stops turning when the throttle

trigger is released.

Check and correct the idle speed setting

at regular intervals. If the drilling tool

continues to rotate when the engine is

idling, have the machine checked by

your servicing dealer. STIHL

recommends STIHL dealers.

Take special care in slippery conditions

– dampness, snow, ice, on slopes or

uneven ground.

Watch out for obstacles: tree stumps,

roots – risk of tripping or stumbling!

Be particularly alert and cautious when

wearing hearing protection because

your ability to hear warnings (shouts,

alarms, etc.) is restricted.

Take breaks when you start getting tired

or feeling fatigue – risk of accidents!

Work calmly and carefully – in daylight

conditions and only when visibility is

good. Proceed with caution, do not put

others in danger.

To reduce the risk of serious or fatal

injury from breathing toxic fumes,

ensure proper ventilation when working

in trenches, hollows or other confined

locations. This reduces the risk of

serious or fatal injury from breathing

toxic fumes.

Stop work immediately if you start

suffering from nausea, headaches,

impaired vision (e.g. your field of vision

gets smaller), impaired hearing,

dizziness, or impaired concentration –

these symptoms may possibly be the

result of too-high exhaust gas

concentration – Risk of accidents!

Operate your power tool so that it

produces a minimum of noise and

emissions – do not run the engine

unnecessarily, accelerate the engine

only when working.

To reduce the risk of fire, do not smoke

while operating or standing near your

power tool. Combustible fuel vapor may

escape from the fuel system.

Dust, fumes and smoke produced while

working may be hazardous to your

health. Wear respiratory protection in

case of heavy dust or smoke emission.

9912BA000 KN

As soon as the engine is

running, the power

machine generates toxic

exhaust gas. These

gases may be odorless

and invisible and may

contain unburned hydro

-

carbons and benzene.

Never run the engine

indoors or in poorly venti

-

lated locations, even if

your model is equipped

with a catalytic converter.

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If your power tool is subjected to

unusually high loads for which it was not

designed (e.g. heavy impact or a fall),

always check that it is in good condition

before continuing work – see also

"Before Starting".

Check in particular that the fuel system

has no leaks and the safety equipment is

fully operative. Never use a power tool

that is no longer safe to operate. In case

of doubt, contact a dealer.

Do not operate your power tool in the

starting throttle position – engine speed

cannot be controlled in this position.

To reduce the risk of injury, do not touch

the drilling tool and drilling spindle

unless the engine is stopped and the

drilling tool is at a standstill.

Hold the machine firmly so that sudden

jolts can be absorbed – only apply a

small amount of pressure when drilling.

Cover drilled holes and secure them.

To reduce the risk of injury, shut off the

engine and engage the drill brake before

changing the drill.

Do not touch machine parts, particularly

the muffler – Risk of burn injuries.

Always shut off the engine before

leaving the unit unattended.

Check drilling tools at regular short

intervals during operation or

immediately if there is a noticeable

change in operating behavior. Replace

damaged or dull drilling tools and blades

immediately.

Vibrations

Prolonged use of the power tool may

result in vibration-induced circulation

problems in the hands (whitefinger

disease).

No general recommendation can be

given for the length of usage because it

depends on several factors.

The period of usage is prolonged by:

– Hand protection (wearing warm

gloves)

– Work breaks

The period of usage is shortened by:

– Any personal tendency to suffer

from poor circulation (symptoms:

frequently cold fingers, tingling

sensations).

– Low outside temperatures.

– The force with which the handles

are held (a tight grip restricts

circulation).

Continual and regular users should

monitor closely the condition of their

hands and fingers. If any of the above

symptoms appear (e.g. tingling

sensation in fingers), seek medical

advice.

Maintenance and Repairs

Service the machine regularly. Do not

attempt any maintenance or repair work

not described in the instruction manual.

Have all other work performed by a

servicing dealer.

STIHL recommends that you have

servicing and repair work carried out

exclusively by an authorized STIHL

servicing dealer. STIHL dealers are

regularly given the opportunity to attend

training courses and are supplied with

the necessary technical information.

Only use high-quality replacement parts

in order to avoid the risk of accidents

and damage to the machine. If you have

any questions in this respect, consult a

servicing dealer.

STIHL recommends the use of original

STIHL replacement parts. They are

specifically designed to match your

model and meet your performance

requirements.

To reduce the risk of injury from

unintentional engine startup, always

shut off the engine and disconnect the

spark plug boot before performing any

repairs, maintenance or cleaning work. –

Exception: Carburetor and idle speed

adjustments.

Do not turn the engine over on the

starter with the spark plug boot or spark

plug removed since there is otherwise a

risk of fire from uncontained sparking.

To reduce the risk of fire, do not service

or store your machine near open flames.

Check the fuel filler cap for leaks at

regular intervals.

Avoid contact with lines

carrying electrical cur

-

rent – Risk of electrical

shock!

Take particular care

when working in stony

areas or ground with

roots.

BT 131

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Use only a spark plug of the type

approved by STIHL and make sure it is

in good condition – see "Specifications".

Inspect the ignition lead (insulation in

good condition, secure connection).

Check the condition of the muffler.

To reduce the risk of fire and damage to

hearing, do not operate your machine if

the muffler is damaged or missing. –

Do not touch a hot muffler since burn

injury will result.

Vibration behavior is influenced by the

condition of the AV elements – check the

AV elements at regular intervals.

Maintenance, replacement, or repair of

the emission control devices and

systems may be performed by any

nonroad engine repair establishment or

individual. However, if you make a

warranty claim for a component which

has not been serviced or maintained

properly, STIHL may deny coverage.

For any maintenance please refer to the

maintenance chart and to the warranty

statement near the end of the instruction

manual.

Fitting activating lever for auger brake

N Insert the activating lever (1) into

the clamp

N Place the holder (2) onto the

activating lever

N Screw in the fastening screws (3)

and tighten

Fit the padding

N Hook the padding (1) with the

tabs (2) into the oblong holes in the

handle frame

N Fold up the padding

N Secure the padding to the

handlebar with the cling strips (3) –

do not jam the throttle cable

Assembling the Unit

3

2

3

1

9912BA001 KN

9912BA002 KN

3

9912BA003 KN

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It may be necessary to correct the

adjustment of the throttle cable after

assembling the machine or after a

prolonged period of operation.

Adjust the throttle cable only when the

machine is completely and properly

assembled.

N Set the throttle trigger to the full

throttle position.

N Rotate the screw in the throttle

trigger clockwise until you feel initial

resistance. Then rotate it another

half turn in the same direction.

This engine is certified to operate on

unleaded gasoline and the STIHL two-

stroke engine oil at a mix ratio of 50:1.

Your engine requires a mixture of high-

quality gasoline and two-stroke air

cooled engine oil.

Use mid-grade unleaded gasoline with a

minimum octane rating of 89 ((R+M)/2)

and no more than 10% ethanol content.

NOTICE

Fuel with an octane rating below 89 may

increase engine temperatures. This, in

turn, increases the risk of piston seizure

and damage to the engine.

The chemical composition of the fuel is

also important. Some fuel additives not

only detrimentally affect elastomers

(carburetor diaphragms, oil seals, fuel

lines, etc.), but magnesium castings and

catalytic converters as well. This could

cause running problems or damage the

engine. For this reason STIHL

recommends that you use only quality

unleaded gasoline!

NOTICE

Gasoline with an ethanol content of

more than 10% can cause running

problems and major damage in engines

and should not be used.

For further details, see

www.STIHLusa.com/ethanol

The ethanol content in gasoline affects

engine speed – it may be necessary to

readjust the carburetor if you use fuels

with various ethanol contents.

WARNING

To reduce the risk of personal injury

from loss of control and/or contact with

the running cutting tool, do not use your

unit with an incorrect idle adjustment. At

correct idle speed, the cutting tool

should not move.

If your machine’s idle speed is

incorrectly adjusted, have your

authorized STIHL servicing dealer

check your machine and make the

proper adjustments and repairs.

The idle speed and maximum speed of

the engine change if you switch from a

fuel with a certain ethanol content to a

fuel with a much higher or lower ethanol

content.

This problem can be avoided by always

using fuel with the same ethanol

content.

To ensure the maximum performance of

your STIHL engine, use a high quality 2-

cycle engine oil. To help your engine run

cleaner and reduce harmful carbon

deposits, STIHL recommends using

STIHL HP Ultra 2-cycle engine oil or ask

your dealer for an equivalent fully

synthetic 2-cycle engine oil.

To meet the requirements of EPA and

CARB we recommend to use STIHL HP

Ultra oil.

Adjusting the Throttle Cable

0000-GXX-2145-A0

Fuel

BT 131

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9

STIHL MotoMix

STIHL recommends the use of STIHL

MotoMix. STIHL MotoMix has a high

octane rating and ensures that you

always use the right gasoline/oil mix

ratio.

STIHL MotoMix uses STIHL HP Ultra

two-stroke engine oil suited for high

performance engines.

For further details, see

www.STIHLusa.com/ethanol

If not using MotoMix, use only STIHL

two-stroke engine oil or equivalent high-

quality two-stroke engine oils that are

designed for use in air cooled two-cycle

engines.

The use of non-seasonal gasoline

blends may increase the potential for

pressure to build in the fuel tank during

operation. For example, using a winter

blend during the summer will increase

pressure in the fuel tank. Always use

gasoline blends appropriate to the

season, altitude and other

environmental factors.

Do not use NMMA or TCW rated (two-

stroke water cooled) mix oils or other

mix oils that state they are for use in both

water cooled and air cooled engines

(e.g., outboard motors, snowmobiles,

chain saws, mopeds, etc.).

WARNING

Take care when handling gasoline.

Avoid direct contact with the skin and

avoid inhaling fuel vapor. When filling at

the pump, first remove the container

from your vehicle and place the

container on the ground before filling. To

reduce the risk of sparks from static

discharge and resulting fire and/or

explosion, do not fill fuel containers that

are sitting in or on a vehicle or trailer.

The container should be kept tightly

closed in order to limit the amount of

moisture that gets into the mixture.

The machine's fuel tank should be

cleaned as necessary.

Fuel mix ages

If not using MotoMix, only mix sufficient

fuel for a few days of work, not to exceed

30 days of storage. Store in approved

fuel-containers only. When mixing, pour

oil into the container first, and then add

gasoline. Close the container and shake

it by hand to ensure proper mix of oil and

gasoline.

WARNING

Shaking fuel can cause pressure to build

in the fuel container. To reduce the risk

of fire and severe personal injury or

property damage from fuel spraying,

allow the fuel container to sit for several

minutes before opening. Open the

container slowly to release any residual

pressures. Never open the fuel

container in the vicinity of any ignition

source. Read and follow all warnings

and instructions that accompany your

fuel container.

Dispose of empty mixing-oil containers

only at authorized disposal locations.

Gaso

-

line

Oil (STIHL 50:1 or equiva

-

lent high-quality oils)

US gal. US fl.oz.

12.6

2 1/2 6.4

5 12.8

BT 131

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10

Preparations

N Before fueling, clean the filler cap

and the area around it to ensure that

no dirt falls into the tank.

N Position the machine so that the

tank cap faces up.

Opening the Tank Cap

N Turn the cap counterclockwise until

it can be removed from the tank

opening.

N Remove the tank cap.

Filling Up with Fuel

Take care not to spill fuel while fueling

and do not overfill the tank.

STIHL recommends you use the STIHL

filler nozzle for fuel (special accessory).

N Fill up with fuel.

Closing the Tank Cap

N Place the cap in the opening.

N Turn the cap clockwise as far as

stop and tighten it down as firmly as

possible by hand.

Engaging the Auger Brake

N Move the activating lever to

position A .

– when starting

– at idling speed

– to unwind a trapped auger

If the auger snags on an obstacle in the

hole (e.g. roots or stones) the machine

will begin to turn counterclockwise – the

activating lever is pressed against the

operator's thigh and thus engages the

auger brake.

Fueling

0000-GXX-0476-A0

002BA447 KN

002BA448 KN

Auger Brake

0000-GXX-1860-A0

A

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11

Disengaging the Auger Brake

N Move the activating lever to

position B

Checking Operation of Auger Brake

The auger brake is subject to normal

wear and tear. Regularly check that it is

operating properly before you start work

and after releasing a trapped auger.

Before starting work and after releasing

a trapped auger

N With the engine running at idle

speed, engage the auger brake and

then open the throttle wide for no

more than 3 seconds – the auger

must not rotate.

If the auger brake fails, have it repaired

immediately by your dealer – STIHL

recommends that this work be

performed by a STIHL servicing dealer.

N Shut off the engine and engage the

auger brake – see "Auger Brake".

N Put the machine down.

N Pull the retaining pin (1) out of the

auger's shank.

N Push the auger (2) onto the drilling

spindle so that the holes (3) line up.

N Push the retaining pin into the hole.

N Spring clip on the retaining pin must

fit snugly around the auger's shank.

0000-GXX-1861-A0

B

Fitting the Auger

9912BA010 KN

1

2

3

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12

Engaging the Auger Brake

N Move the activating lever to

position A . Auger brake is engaged

and auger is blocked.

Controls

1 Throttle trigger lockout

2 Throttle trigger

3 Stop switch with Run and Stop

positions. Depress the stop switch

(…) to switch off the ignition – see

"Function of Stop Switch and

Ignition System".

Function of Stop Switch and Ignition

System

The stop switch is normally in the Run

position, i.e. when it is not depressed:

The ignition is switched on – the engine

is ready to start. Operate the stop switch

to switch off the ignition. The ignition is

switched on again automatically after

the engine stops.

Starting the Engine

N Press the manual fuel pump

bulb (9) at least five times – even if

the bulb is already filled with fuel.

N Press home the choke knob (8) and

turn it to the required position – it

must engage

Cranking

N Place the unit on the ground:

N Check that the auger brake is

engaged.

N Make sure you have a safe and

secure footing.

N Put your left foot on the handle

frame.

N Left hand on the handle frame – do

not touch the throttle trigger or

lockout lever – your thumb should

be under the fan housing.

Starting / Stopping the

Engine

0000-GXX-1860-A0

A

2

1

3

0000-GXX-0477-A0

0000-GXX-0478-A0

g if the engine is cold

< for warm start – also use this posi

-

tion if the engine has been running

but is still cold.

0000-GXX-1862-A0

BT 131

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13

N Hold the starter grip with your right

hand.

N Pull the starter grip slowly until you

feel it engage and then give it a brisk

strong pull.

NOTICE

Do not pull out the starter rope all the

way – it might otherwise break.

N Do not let the starter grip snap back.

Guide it slowly back into the housing

so that the starter rope can rewind

properly.

N Continue cranking until the engine

runs.

As Soon As the Engine Runs

N Depress throttle trigger lockout and

immediately blip the throttle trigger –

the choke knob moves to the run F

position.

NOTICE

Since the auger brake is still engaged,

the engine must be returned to idling

speed immediately – or the clutch might

otherwise be damaged.

N Stand the machine on the tip of the

auger.

N Disengage the auger brake by

moving the activating lever to

position B. Your earth auger is now

ready for operation.

WARNING

Make sure the carburetor is correctly

adjusted. The auger must not rotate

when the engine is idling.

Your machine is now ready for

operation.

Stopping the Engine

N Depress the momentary contact

stop switch – the engine stops –

release the stop switch – it springs

back to the run position.

Other Hints on Starting

Engine stalls in cold start position g or

under acceleration.

N Move the choke knob to < and

continue cranking until the engine

runs.

Engine does not start in warm start

position <

N Move the choke knob to g and

continue cranking until the engine

runs.

If the engine does not start

N Check that all settings are correct.

N Check that there is fuel in the tank

and refuel if necessary.

N Check that the spark plug boot is

properly connected.

N Repeat the starting procedure.

Engine is flooded

N Move the choke knob to F and

continue cranking until the engine

runs.

Fuel tank run until completely dry

N After refueling, depress the manual

fuel pump bulb at least 5 times –

even if the bulb is already filled with

fuel.

N Set the choke knob to suit the

engine temperature.

N Now start the engine.

0000-GXX-1558-A0

0000-GXX-1861-A0

B

BT 131

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14

During Break-In Period

A factory-new machine should not be

run at high revs (full throttle off load) for

the first three tank fillings. This avoids

unnecessary high loads during the

break-in period. As all moving parts

have to bed in during the break-in

period, the frictional resistances in the

engine are greater during this period.

The engine develops its maximum

power after about 5 to 15 tank fillings.

During Operation

After a long period of full throttle

operation, allow the engine to run for a

short while at idle speed so that engine

heat can be dissipated by the flow of

cooling air. This helps protect engine-

mounted components (ignition,

carburetor) from thermal overload.

After Finishing Work

Storing for a short period: Wait for the

engine to cool down. To avoid

condensation, fill the fuel tank and keep

the machine in a dry place, well away

from sources of ignition, until you need it

again. For longer out-of-service periods

– see "Storing the Machine".

Working with shaft extension (special

accessory)

Do not fit the shaft extension until the full

length of the auger is in the hole.

WARNING

Starting a hole with the shaft extension

fitted increases the risk of personal

injury because the unit is then at chest

height and cannot be controlled

properly. For the same reason the shaft

extension must be removed before the

full length of the auger is pulled out of

the hole.

If the auger jams in the drill hole

N Shut off the engine immediately.

N Depress the momentary contact

stop switch – the engine stops –

release the stop switch – it springs

back to the run position.

N Engage the auger brake by moving

the activating lever to position A.

N Rotate the whole machine

counterclockwise to unwind the

auger from the ground.

N After releasing the trapped auger,

check operation of the auger brake

– see “Auger Brake”.

Operating Instructions Releasing a Trapped Auger

0000-GXX-1860-A0

A

BT 131

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15

Filters have an average life of more than

a year. Do not remove the filter cover or

replace the air filter as long as there is no

noticeable loss of power.

If there is a noticeable loss of engine

power.

N Remove padding from the handle

frame.

N Turn the choke knob to g.

N Take out the screws (1).

N Remove the filter cover (2).

N Clean away loose dirt from around

the filter.

N Remove the filter element (3).

N Replace dirty or damaged filter.

N Replace any damaged parts.

Installing the Filter Element

N Install the filter element in the filter

housing and fit the cover.

N Fit the screws and tighten them

down firmly.

N Fit the padding – see "Assembling

the Unit".

Exhaust emissions are controlled by the

design of the engine and components

(e.g. carburation, ignition, timing and

valve or port timing).

Replacing the Air Filter

1

0000-GXX-0482-A0

2

3

4

Engine Management

BT 131

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16

The carburetor has been set at the

factory to provide an optimum fuel-air

mixture under most operating

conditions.

Adjusting Idle Speed

Engine stops while idling

N Warm up the engine for about

3 minutes.

N Turn the idle speed screw (LA)

slowly clockwise until the engine

runs smoothly – the auger must not

rotate.

Auger rotates when engine is idling

N Turn the idle speed screw (LA)

slowly counterclockwise until the

auger stops rotating and then turn

the screw about another 1/2 to 3/4

turn in the same direction.

WARNING

If the auger continues to rotate when the

engine is idling, have your machine

checked and repaired by your servicing

dealer.

N If the engine is down on power,

check the spark arresting screen in

the muffler.

N Wait for the muffler to cool down.

N Take out the screw (4).

N Lift the spark arresting screen (5)

and pull it out.

N Clean the spark arresting

screen (5). If the screen is damaged

or heavily carbonized, install a new

one.

N Refit the spark arresting screen (5).

N Insert the screw (4) and tighten it

down firmly.

N If the engine is down on power,

difficult to start or runs poorly at idle

speed, first check the spark plug.

N Fit a new spark plug after about 100

operating hours – or sooner if the

electrodes are badly eroded. Install

only suppressed spark plugs of the

type approved by STIHL – see

"Specifications".

Removing the Spark Plug

N Remove the cover (1).

N Pull off the spark plug boot (2).

N Unscrew the spark plug (3).

Adjusting the Carburetor

0000-GXX-0495-A0

Spark Arresting Screen in

Muffler

0000-GXX-0486-A0

4

5

Spark Plug

3

2

1

0000-GXX 0537-A0

BT 131

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17

Checking the Spark Plug

N Clean dirty spark plug.

N Check electrode gap (A) and

readjust if necessary – see

"Specifications".

N Rectify the problems which have

caused fouling of the spark plug.

Possible causes are:

– Too much oil in fuel mix.

– Dirty air filter.

– Unfavorable running conditions.

WARNING

Arcing may occur if the adapter nut (1) is

loose or missing. Working in an easily

combustible or explosive atmosphere

may cause a fire or an explosion. This

can result result in serious injuries or

damage to property.

N Use resistor type spark plugs with a

properly tightened adapter nut.

Installing the Spark Plug

N Screw the spark plug (3) into the

cylinder.

N Tighten down the spark plug (3) with

the combination wrench.

N Press the boot (2) firmly onto the

spark plug.

N Fit the cover (1) and screw it down

firmly.

If engine running behavior is still

unsatisfactory after the air filter has been

serviced and the carburetor and throttle

cable have been adjusted correctly, the

cause may also be in the muffler.

Have the muffler checked for

contamination (coking) by a servicing

dealer!

STIHL recommends that maintenance

and repair work be carried out only by

authorized STIHL dealers.

000BA039 KN

A

1

000BA045 KN

Engine Running Behavior

BT 131

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18

Check grease level after every 50 hours

of operation and re-lubricate if

necessary.

N Remove the screw plug (1).

N If no grease can be seen on the

inside of the screw plug (1): Screw

the tube (2) of STIHL gear lubricant

(special accessory) into the filler

hole.

N Squeeze about 5

-

10 g (1/5

-

2/5

oz) grease into the gearbox.

NOTICE

Do not completely fill the gearbox with

grease.

N Unscrew the tube (2).

N Insert the screw plug (1) and tighten

it down firmly.

For periods of about 3 months or longer

N Remove the auger.

N Drain and clean the fuel tank in a

well ventilated area.

N Dispose of fuel properly in

accordance with local

environmental requirements.

N Run the engine until the carburetor

is dry – this helps prevent the

carburetor diaphragms sticking

together.

N Thoroughly clean the machine.

N Store the machine in a dry and

secure location Keep out of the

reach of children and other

unauthorized persons.

Lubricating the Gearbox

1

9912BA019 KN

9912BA020 KN

Storing the Machine

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